The present invention relates to a cleaning apparatus for various types of printing presses, which cleans the printing cylinders, e.g., a blanket cylinder and an impression cylinder, and rollers, e.g., a form roller and a vibrating roller.
Various types of printing presses, e.g., an offset printing press and an intaglio printing press, have printing cylinders, e.g., a plate cylinder, a blanket cylinder, and an impression cylinder, and rollers, e.g., a form roller and a vibrating roller. During printing, foreign matters, e.g., ink dust and paper dust attach to the circumferential surfaces of these printing cylinders and rollers to degrade the quality of printed matter. Hence, the printing press is provided with a cleaning apparatus for removing these foreign matters.
The cleaning apparatus of this type has a supply roll and a take-up roll. The supply and take-up rolls extend in the axial direction of a printing cylinder to be cleaned, e.g., the blanket cylinder, to be close to its circumferential surface. Each roll has two end portions rotatably supported by the bearings of the frame. A belt-like cleaning web (to be merely referred to as a web hereinafter) constituted by an unwoven fabric or the like is wound on the supply roll. The web is drawn from the supply roll by rotating the take-up roll with a drive unit, pressed against the circumferential surface of the blanket cylinder with a guide roller or a pad provided between the supply and take-up rolls, and taken up by the take-up roll.
With this arrangement, when the blanket cylinder is rotated and the take-up roll is intermittently rotated to intermittently drive the web, the foreign matters attaching to the circumferential surface of the blanket cylinder are wiped with the web and transferred to the web. The web after the wiping operation is taken up by the take-up roll with the foreign matters attaching to it.
When the ink roller is to be cleaned, for example, a cleaning apparatus for scraping the foreign matters attaching to the circumferential surface of the ink roller with a doctor is employed. More specifically, in a cleaning state, the doctor is obliquely provided between the supply and take-up rolls with its distal end facing upward. The doctor is separated from the circumferential surface of the ink roller, so that its proximal end portion is brought into contact with the web traveling from the supply roll to the take-up roll and that its distal end opposes to contact the circumferential surface of the ink roller.
With this arrangement, after the distal end of the doctor opposes to contact the circumferential surface of the ink roller, when the ink roller is rotated and the take-up roll is intermittently rotated, the web is intermittently driven. Then, the foreign matters attaching to the circumferential surface of the ink roller are scraped by the distal end of the doctor, moved downward on the flat surface of the doctor, and transferred from the proximal end portion of the doctor to the web. The web passing by the proximal end portion of the doctor is taken up by the take-up roll with the foreign matters attaching to it.
In the cleaning apparatus of this type, if the apparatus is kept mounted on the frame when it is not in use, the operation of the printing press is hindered. Therefore, the entire cleaning apparatus is removed from the printing press and stored. When the web wound on the supply roll runs out, the empty supply roll is removed from the support members of the apparatus frames and exchanged for a new supply roll having a web wound on it. Simultaneously, the take-up roll having the web fully wound on it is exchanged for a new empty take-up roll.
Therefore, conventionally, the cleaning unit is constituted by a supply roll, a take-up roll, and apparatus frames supporting the two rolls and a doctor. The cleaning unit is detachably mounted on the frame of the printing press, thereby allowing storage of the cleaning unit and exchange of the web.
However, in the conventional cleaning apparatus, since all the air cylinders and levers for driving the take-up roll are provided on the cleaning unit side, the entire cleaning unit is considerably heavy. Hence, to clean a roller, this heavy cleaning unit must be mounted on or removed from the frame of the printing press. Regarding exchange of the web, not only this heavy cleaning unit but also the pipes of the air cylinders for driving the take-up roll must be mounted on and removed from the frame of the printing press, requiring a time-consuming heavy labor.